Sandy Bauers

Inquirer GreenSpace Columnist

A draft report by an international group of hundreds of scientists finds with more certainty than ever that human activity is largely responsible for the warming of the earth's average surface temperature, leading to altered weather patterns, the melting of glaciers and sea ice, and more.

The group, the Intergovernmental Panel on Climate Change, releases reports every five or six years and are considered the definitive works on climate change because they analyze and synthesize peer-reviewed work on climate change. The panel first addressed whether climate change was happening, then why, then what to expect going forward. In 2007, the panel won the Nobel Peace Prize, along with Al Gore.

The next report, the panel's fifth, isn't due for several months, although a small portion of it could be released next month. But some news outlets, including the New York Times, obtained advance draft copies. Note the word "draft." Things could change. But ...

The Times wrote that this latest report "emphasizes that the basic facts about future climate change are more established than ever, justifying the rise in global concern. It also reiterates that the consequences of escalating emissions are likely to be profound."

It quoted the report as saying, “It is extremely likely that human influence on climate caused more than half of the observed increase in global average surface temperature from 1951 to 2010. There is high confidence that this has warmed the ocean, melted snow and ice, raised global mean sea level and changed some climate extremes in the second half of the 20th century.”

Climate change deniers often cite a recent -- as in the past decade or so -- slowdown in temperature changes as proof that climate change is not happening. However, the report nixes that, saying the slowdown is due to short-term factors.

The Times story noted: "The 2007 report found “unequivocal” evidence of warming, but hedged a little on responsibility, saying the chances were at least 90 percent that human activities were the cause. The language in the new draft is stronger, saying the odds are at least 95 percent that humans are the principal cause."

Also: "On sea level, which is one of the biggest single worries about climate change, the new report goes well beyond the assessment published in 2007, which largely sidestepped the question of how much the ocean could rise this century." It now says sea levels could rise three feet -- a global average -- by the end of the century if current emission levels continue.

Sea level in New Jersey is rising faster, because the land there is sinking -- a phenomenon known as "subsidence." During the last Ice Age, the land under the massive glacier sank. The land ahead of the glacier -- the ice stopped roughly at what is now the northern border of New Jersey -- squished up, much as a mattress would if you sat on it.

Now, land to the north of New Jersey is rising, and land in New Jersey and south is sinking.